Bi-planar persuader

ABSTRACT

Surgical instruments for spinal surgery. More specifically, a bi-planar rod persuader for urging a spinal rod into a screw, and methods regarding the same. The bi-planar rod persuader may include an implant holder, which may also include a holding sleeve. A securing foot may be attached to the distal end of the holding sleeve, and the holding sleeve may also include a threaded opening at the proximal end for receiving a stem that drives the securing foot between a first position and second position. The implant holder may also include a threaded part to engage a reduction knob. A handle assembly may also be provided, which may include two pivotally attached arms. A rod hook may be connected to one of the arms and a guide attached to the other of the arms.

BACKGROUND

The spinal column is a highly complex system of bones and connectivetissues that provides support for the body and protects the delicatespinal cord and nerves. The spinal column includes a series of vertebralbodies stacked together. An intervertebral disc is positioned betweeneach vertebral body, and these intervertebral discs cushion and dampencompressive forces exerted upon the spinal column.

However, when there is a spinal disorder, procedures are performed tosurgically correct and stabilize spinal curvatures or to facilitatespinal fusion. Spinal column disorders include scoliosis, kyphosis,excess lordosis, spondylolisthesis, and other disorders caused byabnormalities, disease or trauma, such as ruptured or slipped discs,degenerative disc disease, fractured vertebra, and the like. Patientsthat suffer from such conditions usually experience extreme anddebilitating pain, as well as diminished nerve function.

Spinal fixation is one surgical technique that may be used toeffectively treat the above-described conditions and, in many cases, torelieve pain. Spinal fixation involves the use of spinal implants and/ormechanical immobilization to fuse two or more vertebral bodies of thespinal column. Furthermore, spinal fixation may be used to alter thealignment of adjacent vertebral bodies relative to one another so as tochange the overall alignment of the spinal column.

One such spinal fixation technique involves immobilizing the spine usingorthopedic stabilizing rods, commonly referred to as spinal rods, whichare positioned generally parallel to the spine. Each rod is attached tovarious vertebra along the length of the spine by way of vertebraengaging spinal implants which may include, but are not limited to,pedicle screws, pedicle hooks, transverse process hooks, sublaminarhooks, etc. The spinal implants commonly include a U-shaped rodreceiving channel for receiving the spinal rod therein. Moreover, therod receiving channel often includes a means for receiving a fasteningmechanism, for example, a set screw, a locking screw, or a cam, tosubsequently clamp and fix the position of the spinal rod with respectto the spinal implant.

Instruments are commonly used to insert the spinal rod into position inthe receiving channel. Surgeons, however, have often encounteredconsiderable difficulty when using these instruments because of problemsassociated with aligning the spinal rod(s) within the rod receivingchannel(s) formed in the head(s) of the spinal implant(s). For example,the heads of the spinal implants may be out of vertical and/orhorizontal alignment with one another due to the curvature of the spineor the size and shape of each vertebrae.

SUMMARY

The present disclosure relates to a medical device for reducing a spinalrod into the head of a screw, and methods for using such device. Thesedevices and methods may be used with surgeries involving spinalfixation.

An example medical device for reducing a spinal rod into the head of apedicle screw includes an implant holder and a handle assembly. Theimplant holder includes a holding sleeve, which has a proximal end and adistal end. The holding sleeve is configured such that a securing footis pivotally attached to the distal end. Furthermore, the proximal endof the holding sleeve includes a threaded opening, into which a stem isinserted. For example, the stem has a proximal end and distal end. Thestem drives the securing foot between a first position and a secondposition. The implant holder also includes a threaded part that extendsat a predetermined angle from the proximal end of the holding sleeve.This threaded part is adapted to engage a complementary threaded regionof a reduction knob. The handle assembly includes two pivotally attachedarms. A rod hook is connected to one of the arms, and a guide isattached to the other arm.

The guide is adapted to slidably engage the threaded part. The rod hookis moveable in a first direction by threaded interaction of thereduction knob with the threaded part. The rod hook is moveable in asecond direction that is different than the first direction throughpivotal motion of the arms.

The distal end of the stem may optionally include a spherical shape anda ridge area, and the proximal end of the stem may include a securingcap. For example, the securing cap may include a recessed portion, whichhas a known geometric shape for insertion of a tightening instrument,such as a T25 driver. The stem also may include a threaded region for apredetermined distance on the part of the stem proximate to the securingcap. This predetermined distance is optionally less than the length ofthe stem.

The securing foot is moveable between a first position and a secondposition. For example, the securing foot is in the first position whenthe threaded regions of the stem and the holding sleeve are unthreaded.The securing foot is optionally moveable to a second position when thestem is rotated therein the threaded opening of the holding sleeve. Therotation of the stem into the threaded opening of the holding sleeve mayengage the securing foot to a screw head. The portion of the securingfoot engaging the screw optionally has a known geometry and iscomplementary to the known geometry of the screw.

The distal end of the holding sleeve optionally includes three sides,and one of the three sides may have a recessed portion. The two of thethree unrecessed sides of the holding sleeve may include concave areasfor engaging a screw. The distal end of the holding sleeve may alsoinclude a ridge portion for engaging a screw.

A guide may optionally be attached to the rod hook with a pivot screw.The distal end of the rod hook may include two concave portions that maybe used to engage a spinal rod. Once the rod hook engages a spinal rod,the spinal rod may be moved in a first direction or a second direction.The first direction may be defined as substantially parallel along anaxis defining the threaded part. On the other hand, the second directionmay be defined by an axis that may be approximated by an arc, and thesecond direction is substantially perpendicular to the axis defining thefirst direction. The threaded part of the implant holder may bepositioned at a predetermined angle, and that predetermined angle mayoptionally be approximately 12°.

An adapter rod may also be provided. For example, the adapter rod mayhave a proximal end and a distal end, and both the proximal end anddistal end may have a known geometry. The distal end of the adapter rodmay optionally be engaged with the recessed portion of the reductionknob. To advance the reduction knob along the threaded part in a firstdirection, the adapter rod may be rotated. This advancement of thereduction knob along the threaded part in a first direction optionallycauses a spinal rod to engage a pedicle screw. The threaded part of theholding sleeve may include the use of a modified square thread measuringapproximately 10°.

The reduction knob may optionally be comprised of polyether ether ketone(PEEK). The threaded portion of the holding sleeve may be comprised ofdiamond-like carbon coating.

Another example medical device for reducing a spinal rod into the headof a pedicle screw includes an implant holder and a handle assembly. Theimplant holder includes a holding sleeve, which has a proximal end and adistal end. The holding sleeve is configured such that a securing footis pivotally attached to the distal end. Furthermore, the proximal endof the holding sleeve includes a threaded opening, into which a stem isinserted. For example, the stem has a proximal end and distal end. Thestem drives the securing foot between a first position and a secondposition. The implant holder also includes a threaded part that extendsat a predetermined angle from the proximal end of the holding sleeve.This threaded part is adapted to engage a complementary threaded regionof a reduction knob. The handle assembly includes two pivotally attachedarms. A rod hook is connected to one of the arms, and a guide isattached to the other arm.

The guide is adapted to slidably engage the threaded part. The rod hookis moveable in a first direction by threaded interaction of thereduction knob with the threaded part. The first direction is defined assubstantially parallel along an axis defining the threaded part. The rodhook is also moveable in a second direction that is different than thefirst direction through pivotal motion of the arms. The second directionis defined as substantially parallel to an axis that may be approximatedby an arc created by the movement of the rod hook. The second directionis substantially perpendicular to the axis defining the first direction.

Also provided is a method for reducing a spinal rod into the head of ascrew. The method includes attaching a rod hook to a spinal rod. Asecuring foot is then advanced from a first position to a secondposition, in order to attach the securing foot and holding sleeve to ascrew. The method also includes moving the rod hook in the firstdirection, and then moving the rod hook in the second direction that isdifferent than the first direction. The movement in the first directionand second direction may be iterative to achieve a final position of therod.

A locking cap may be optionally introduced to secure the spinal rod tothe screw. The method may also include advancing the securing foot fromthe second position to the first position to detach the securing footand holding sleeve from the screw.

These and other features and advantages of the implementations of thepresent disclosure will become more readily apparent to those skilled inthe art upon consideration of the following detailed description andaccompanying drawings, which describe both the preferred and alternativeimplementations of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, like reference numbers and designations in the variousdrawings indicate like elements.

FIG. 1 is a perspective view showing an example medical device forreducing a rod into the head of a screw;

FIG. 2A is a perspective view showing an example implant holder;

FIGS. 2B-2C are perspective views showing example holding sleeves;

FIG. 2D is a perspective view showing an example securing foot;

FIG. 2E is a schematic showing an example stem;

FIG. 2F is a perspective view showing an example reduction knob;

FIG. 2G is a schematic showing an example adapter rod;

FIGS. 3A-3C are perspective views showing example implant holders forengaging a screw;

FIGS. 4A-4C are perspective views showing example handle assemblies;

FIG. 5 is a perspective view showing an example rod hook of FIGS. 4A-4C;

FIGS. 6A-6G are perspective views showing example medical devices forreducing a rod into the head of a screw; and

FIG. 7 illustrates an operational flow of reducing a rod into the headof a screw, as depicted in FIGS. 6A-6G.

DETAILED DESCRIPTION

Implementations of the present disclosure now will be described morefully hereinafter. Indeed, these implementations can be embodied in manydifferent forms and should not be construed as limited to theimplementations set forth herein; rather, these implementations areprovided so that this disclosure will satisfy applicable legalrequirements. As used in the specification, and in the appended claims,the singular forms “a,” “an,” and “the,” include plural referents unlessthe context clearly indicates otherwise. The term “comprising” andvariations thereof as used herein is used synonymously with the term“including” and variations thereof and are open, non-limiting terms.

In performing a wide range of back surgeries, surgeons are oftenrequired to make use of pedicle screws and rods. These screws and rodsare components of rigid stabilization systems, which tend to beintrusive to surrounding tissue and vasculature systems. When workingwith these rigid stabilization systems, surgeons often use instrumentsto insert the spinal rod into position in the receiving channel of ascrew. Surgeons, however, have often encountered considerable difficultyin maneuvering the spinal rod into position in the receiving channel.The present disclosure provides devices and methods for urging spinalrods into the rod receiving channel formed in the spinal implants, whichincludes the capability to move the spinal rod in more than onedirection. The surgeon is also able to use these disclosed devices andmethods with only one hand.

FIG. 1 shows an example medical device 100 for reducing a rod into thehead of a screw or other bone attachment device. The example medicaldevice 100 may include an implant holder 120, a handle assembly 400, arod hook 408, and a guide 410. As shown in FIG. 1, the implant holder120 includes a holding sleeve 200 with a securing foot 206 pivotallyattached to a distal end of the holding sleeve 200. The holding sleeve200 further includes a threaded opening 208 at a proximal end. Thethreaded opening 208 is adapted to receive a stem 210 that drives thesecuring foot 206 between a first position and a second position. Theimplant holder 120 also includes a threaded part 216 extending at apredetermined angle from the proximal end 202 of the holding sleeve 200.The threaded part 216 is adapted to engage a complementary threadedportion of a reduction knob (not shown in FIG. 1).

The securing foot 206 may be adapted to engage the head of a screw 304.In order for the securing foot 206 to fully engage the head of a screw304, the implant holder is fully unthreaded so that the securing foot206 is in the first or “open” position. The implant holder 120 may thenbe engaged on the side of the screw head 304 opposite the rod 500. Oncethe implant holder 120 is fully seated on the screw head 304, the stem210 may be tightened by one's fingers or an appropriate driver. In orderto ensure that the implant holder is securely fit atop of the screwhead, the medical professional or other appropriate personnel maylightly pull up on the implant holder 120.

The handle assembly 400 includes two pivotally attached arms 402 and404. A rod hook is 408 is connected to arm 402. The guide 410 isattached to arm 404. The guide 410 is adapted to slidably engage thethreaded part 216, such that the rod hook 408 is moveable in a firstdirection. Movement in a first direction occurs by threaded interactionof the reduction knob with the threaded part 216. Further, pivotalmotion of the arms 402 and 404 causes the rod hook 408 to be moveable ina second direction different than the first direction. A more detaileddiscussion of the movement of the rod caused by the device 100 isdescribed below.

The handle assembly 400, including the guide 410 and rod hook 408, maybe placed over the implant holder so that the rod hook 408 is positionedon the same side as the rod 600. The handle assembly 400 may be engagedwith the implant holder 120, and the medical professional or otherappropriate personnel squeezes arms 402 and 404 of the handle assemblyuntil the rod hook 408 meets the top of the rod 500. Once the rod hook408 meets the top of the rod 500, the reduction knob 214 (not shown) maythen be threaded onto the proximal end of the implant holder 120.

The reduction knob 214 (not shown) may then be further advancedclockwise to achieve advancement of the rod hook 408 in the firstdirection. The arms 402 and 404 of the handle assembly may be squeezedto advance the rod hook 408 in a second direction. Advancement in thefirst and/or second direction may continue until the rod 500 engages thebottom of the rod slot in the head of the screw 304. Once the rod 500has engaged the head of the screw 304 and is positioned correctly, alocking cap (not shown) may be introduced and tightened. The implantholder 120, handle assembly 400, rod hook 408, and guide 410 may then beremoved by loosening the stem 210 on the implant holder to disengage thesecuring foot 206 from the head of the screw 304.

The above-described components of the medical device 100 will bedescribed in further detail below. The example medical device 100 mayprovide reduction of a rod into the head of a screw when the rod is outof alignment in up to two different planes during spinal surgery. Thismedical device 100 may be used in the posterior thoracic and lumbarspine region for degenerative and deformity correction.

Referring now to FIG. 2A, an example implant holder 120 is shown. Theimplant holder 120 includes a holding sleeve 200 having a proximal end202 and a distal end 204. Example holding sleeves 200 are shown in FIGS.2B and 2C. During spinal surgery, the holding sleeve 200 and securingfoot 206 may be attached to a screw. Thus, the securing foot 206provides for a secure fit, as well as a fit that does not hinder amedical professional's access to all the desired features used on thescrew. For example, once a rod is reduced into the head of the screw,the medical professional must be able to introduce some lockingmechanism, including but not limited to a locking screw, to lock the rodand screw together. Because the holding sleeve 200 and securing foot 206are secured to only one side of the screw, the holding sleeve 200provides access to the screw for introduction of a locking mechanism,once the rod is reduced into the head of the screw.

Referring to FIG. 2C, an example holding sleeve 200 is shown with thedistal end 204 of the holding sleeve 200 as optionally defined on threesides. One side of the three sides may have a recessed portion 236. Thetwo of the three unrecessed sides 238 may include concave areas forengaging a screw.

A securing foot 206 is pivotally attached to the distal end 204 of theholding sleeve 200. An example securing foot 206 is shown in FIG. 2D. Inorder to facilitate engagement of the distal end 204 of the holdingsleeve 200 with a screw head, the portion of the securing foot 206engaging the screw may have a known geometry 218. This known geometry218 of the securing foot 206 may be complementary to the known geometryof the screw to provide a secure fit between the securing foot 206 andthe screw, as well as maximizes the contact area between the securingfoot 206 and the screw. This known geometry 218 may vary to accommodatevarious screw designs, architecture, and/or other screw embodiments.

The holding sleeve 200 further includes a threaded opening 208 at theproximal end 202 of the holding sleeve 200. The threaded opening 208 isadapted to receive a stem 210 that drives the securing foot 206 betweena first position and a second position. An example stem 210 is shown inFIG. 2E. The stem 210 may include a proximal end 226 and a distal end224. The distal end 224 of the stem 210 may optionally include aspherical shape 228 and a ridge area 230. The shape on the distal end224 of the stem 210 provides for ease of use when a medical professionalrotates the stem to engage the securing foot 206 with the head of ascrew. Further, the shape on the distal end 224 of the stem 210 providesa uniform shape that does not change the position and/or shape of stem210 as stem 210 advances.

The stem 210 may optionally provide a securing cap 232 on the proximalend 226 of the stem 210. The superior portion of the securing cap 232may include a recessed portion 220. The recessed portion 220 may beadapted to a known geometric shape for insertion of a tighteninginstrument therein. For example, a T25 driver 502 (as shown in FIGS.6E-6F) may be used as a tightening instrument. Other appropriate orrelevant tightening instruments may be used. Further, the recessedportion 220 of the stem 210 may be adapted to any known geometric shapefor use with any complementary tightening instrument. A portion of thestem 210 proximate to the securing cap 232 may define a threaded region234 for a predetermined distance, as shown in FIG. 2E. For example, thepredetermined distance of the threaded region 234 is less than thelength of the stem 210. This predetermined distance ensures that themale threads exit the female threads in such a way that prevents theuser from over-loosening the stem and damaging the instrument.Similarly, the length 235 between the bottom of the securing cap 232 andthe distal end 224 is predefined to act as a safety stop in order toprevent over-tightening of the stem 210 within the implant holder 120.

The implant holder 120 further includes a threaded part 216 extending ata predetermined angle 212 from the proximal end 202 of the holdingsleeve 200. For example, the predetermined angle 212 optionally measuresapproximately 12°. Access during spinal surgery may be limited, so theangle measurement of 12° allows a medical professional adequate access.The threaded part 216 is adapted to engage a complementary threadedportion of a reduction knob 214. An example reduction knob 214 is shownin FIG. 2F.

Referring now to FIG. 2G, an example adapter rod 250 is shown. Theadapter rod 250 may have a proximal end 252 and distal end 254. Both theproximal end 252 and distal end 254 of the adapter rod 250 may bedefined in a known geometry. The distal end 254 may be engaged with therecessed portion 222 of the reduction knob 214. Any known geometry maybe chosen for the distal end 254 or proximal end 252 of the adapter rod250, or for the recessed portion 222 of the reduction knob 214. Theadapter rod 250 may be rotated to advance the reduction knob 214 alongthe threaded part 216 in the first direction. Advancement of thereduction knob 214 along the threaded part 216 in the first directioncauses the spinal rod to engage the screw. The threaded part 216 may bedefined by a modified square thread measuring approximately 10°. Amodified square thread may be used to allow medical professionals moreefficiency and ease of use when engaging the complementary threads ofthe reduction knob 214 and threaded part 216.

The reduction knob 214 may optionally be comprised of polyether etherketone (PEEK). This implant-grade PEEK material provides smooth threadedinteraction along stainless steel and other metals. Implant-grade PEEKmaterial also provides strength with minimized friction. The threadedportion 216 of the holding sleeve 200 may be coated in diamond-likecarbon (DLC) coating or any other surface treatment to minimize frictionor wear. DLC coating provides minimized friction on the threaded part216, provides long-lasting threads, and protects the threaded part 216(especially the parallel flat surfaces) as it slides through the guide410 under extreme torque loads that result from maintaining the positionof rod 500. These and the other components of the medical device may becomprised of any other metals or materials appropriate for surgicalinstruments and devices, including but not limited to stainless steel,titanium, CoCrMo, carbon fiber, and aluminum.

Referring now to FIGS. 3A-3C, there is illustrated an example engagementbetween the implant holder 129 and a screw 394 of the presentdisclosure. The securing foot 206 may have a first position 300 or asecond position 302. For example, the first position 300 is optionallydefined as wherein the threaded regions of the stem 210 and holdingsleeve 200 are unthreaded. FIG. 3A shows an example implant holder 120with the threaded regions of the stem 210 and holding sleeve 200 asunthreaded, and the securing foot 206 is optionally in a disengagedposition.

FIG. 3B illustrates an example screw 304 engaged to a ridge portion 240.The distal end 204 of the holding sleeve 200 may include the ridgeportion 240 for engaging a screw. During surgery, a medical professionalmay engage a screw with holding sleeve 200, and the ridge portion 240may provide guidance to the medical professional to know when theholding sleeve 200 is seated atop the screw 304.

The securing foot 206 may also be defined as in a second position 302wherein the stem is rotated therein the threaded opening of the holdingsleeve 200. Referring to FIG. 3C, an example implant holder is shownwith the threaded region 234 of the stem 210 and holding sleeve 200 asengaged. For example, rotation of the stem 210 into the threaded opening208 of the holding sleeve 200 engages the securing foot 206 to the headof a screw 304.

Referring now to FIGS. 4A-4C, example handle assemblies 400 are shown.The handle assembly 400 includes two pivotally attached arms 402 and404. A rod hook 408 is connected to arm 402. A guide 410 is attached toarm 404. The guide 410 is adapted to slidably engage a threaded part ofthe implant holder (FIG. 2A), such that the rod hook 408 is pivotallymoveable in the second direction when the guide 410 engages the threadedpart. For example, pivotal motion of the arms 402 and 404 causes the rodhook 408 to be moveable in the second direction, which is different thanthe first direction. As noted above, the first direction may be definedas substantially parallel along an axis defining the threaded part. Thesecond direction may be defined as substantially parallel along an axisthat may be approximated by an arc created by the movement of the rodhook 408. The guide 410 may be defined to cease travel of the rod hook408 and the spinal rod in the second direction once the pivotallyattached arms 402 and 404 are fully squeezed together. FIG. 5illustrates the rod hook 408 in greater detail. As shown in FIG. 5, thedistal end 418 of the rod hook 408 may include two concave portions 422for engaging a spinal rod.

A lever 412 may also be provided with locking mechanisms along thelength of lever 412. Complementary locking grooves may be provided onthe proximal end of arm 404 to securely lock the handle assembly as themedical professional squeezes pivotally attached arms 402 and 404. Onceat a position to stop, the medical professional can release thesqueezing force, and the handle assembly may optionally lock into thelatest position. This feature allows the medical professional tomaintain a one-handed operation during the spinal surgery. Further,springs 406 may be provided between arms 402 and 404 to ensure aspring-loaded effect once the lever 412, if provided, is released fromthe locked position. When lever 412 is provided, the medicalprofessional may engage and disengage lever 412 as necessary and asappropriate for the particular clinical situation. As shown in FIGS.4A-4C, a guide 410 is optionally attached to the rod hook 408 with apivot screw 414.

The arms 402 and 404 may be attached by screw 424, as shown in FIG. 4B.Arm 402 may be attached to rod hook 408 by screw 420. The guide 410 maybe attached to the rod hook 408 by pivot screw 414, and the guide 410may optionally be attached to arm 404 by screw 416. Screws 414, 416,420, and 424 at the respective connection joints allow the rod hook 408to move in the same direction as arms 402 and 404 when arms 402 and 404are squeezed.

In accordance with another embodiment of the current disclosure themedical device may include an implant holder, a handle assembly, a rodhook, and a guide. The implant holder includes a holding sleeve 200, andthe holding sleeve 200 has a proximal end 202 and a distal end 204. Asecuring foot 206 is pivotally attached to the distal end 204 of theholding sleeve 200. The holding sleeve 200 further includes a threadedopening 208 at the proximal end 202 of the holding sleeve 200. Thethreaded opening 208 is adapted to receive a stem 210 that drives thesecuring foot 206 between a first position and a second position. Theimplant holder further includes a threaded part 216 extending at apredetermined angle 212 from the proximal end 202 of the holding sleeve200. The threaded part 216 is adapted to engage a complementary threadedportion of a reduction knob 214.

The handle assembly 400 includes two pivotally attached arms 402 and404. A rod hook 208 is connected to arm 402. A guide 410 is attached toarm 404. The guide 410 is adapted to slidably engage the threaded part216, such that the rod hook 408 is moveable in a first direction.Movement in a first direction occurs by threaded interaction of thereduction knob 214 with the threaded part 216. Movement in the firstdirection is defined as substantially parallel along an axis definingthe threaded part. Further, pivotal motion of the arms 402 and 404causes the rod hook 408 to be moveable in a second direction differentthan the first direction, as described above.

In accordance with the present disclosure, there is also provided amethod for reducing a rod into the head of a screw. Example methods areillustrated by FIGS. 6A-6G and an operational flow chart 700 in FIG. 7.The securing foot 206 and holding sleeve 200 may be attached a head of ascrew 304 by the engaging stem (FIG. 6A; 702). The rod hook 408 may thenbe attached to the rod 500 (FIG. 6A; 704). The rod 500 may include anytype of spinal rod. The method further includes advancing a securingfoot 206 from a first position to a second position to attach thesecuring foot 206 and holding sleeve 200 to a screw 304 (FIG. 6A; 706).The rod hook 408 is moved in the first direction (FIGS. 6B and 6C; 708),and then moved in the second direction different than the firstdirection (FIGS. 6C and 6D; 710). For example, the first direction maybe defined as substantially parallel along an axis defining the threadedpart of the implant holder.

The rod hook 408 may be moved in the second direction by squeezing twopivotally attached arms 402 and 404. A lever 412 may also be providedwith locking mechanisms along the length of lever 412 (FIG. 6E; 712).Complementary locking grooves may be provided on the proximal end of arm404 to securely lock the handle assembly as the medical professionalsqueezes pivotally attached arms 402 and 404. Once at a position tostop, the medical professional can release the squeezing force, and thehandle assembly may optionally lock into the latest position. Thisfeature allows the medical professional to maintain a one-handedoperation during spinal surgery.

A guide 410 may be adapted to slidably engage the threaded part 216 ofthe implant holder. The rod hook 408 is optionally moveable in the firstdirection by threaded interaction of the reduction knob 214 with thethreaded part 216 (FIG. 6E; 714). Advancement in the first direction mayreduce a rod 600 into a screw 304. A locking cap, or any otherappropriate locking mechanism, may optionally be introduced to securethe rod 600 to the screw 304 (FIG. 6F; 716). Further, the securing foot206 may be advanced from the second position to the first position todetach the securing foot 206 and holding sleeve 200 from the screw 304(FIG. 6G; 718). In this method, advancement in the first direction mayoccur prior to advancement in the second direction. Alternatively,advancement in the second direction may occur prior to advancement inthe first direction. Still further, the movement in the first and seconddirection may be iterative. A medical professional may adjustadvancements in the various directions based on his expertise andrelevant clinical settings.

In the above, the device 100 has been described as being secured to thescrew 304 by performing a sequence of steps to attach and secure thesecuring foot 206 to the head of the screw 304. It is noted that theremoval of the device 100 from screw 304 may be performed in a differentreverse order than the order by which the device 100 was secured to thescrew 304. As such, the user is enabled to can remove the device fromthe surgical site much more quickly during use.

Many modifications and other embodiments of the disclosure set forthherein will come to mind to one skilled in the art to which thisdisclosure pertains having the benefit of the teachings presented in theforegoing description. Therefore, it is to be understood that thedisclosure is not to be limited to the specific embodiments disclosedand that modifications and other embodiments are intended to be includedwithin the scope of the appended claims. Although specific terms areemployed herein, they are used in a generic and descriptive sense onlyand not for purposes of limitation.

That which is claimed:
 1. A medical device adapted to be secured to ascrew, comprising: an implant holder that includes a holding sleeve anda securing foot pivotally attached to a distal end of the holdingsleeve, the holding sleeve defining a threaded opening at a proximal endthereof that receives a stem that drives the securing foot between afirst position and a second position, the implant holder including athreaded part extending at an angle relative to the proximal end of thesleeve, the stem having a securing cap extending from a proximal endthereof such that a distance between the securing cap and a distal endof the stem is predetermined to prevent over-tightening orover-loosening of the stem, a portion of the stem proximate to thesecuring cap defining a threaded region extending over less than alength of the stem, wherein a portion of the securing foot has a knowngeometry complementary to a known geometry of the screw, and wherein thesecuring foot is sized and configured to be engaged to the screw when inthe second position and disengaged from the screw when in the firstposition.
 2. The medical device of claim 1, wherein the securing foot isin the first position when the threaded region of the stem and thethreaded opening of the holding sleeve are uncoupled.
 3. The medicaldevice of claim 1, wherein the securing foot is in the second positionwhen the stem is rotated about the threaded opening of the holdingsleeve.
 4. The medical device of claim 1, wherein the securing foot issized and configured to engage only one side of a head of the screw. 5.A medical device for reducing a rod into a head of a screw, comprising:an implant holder that includes a holding sleeve, a securing footpivotally attached to a distal end of the holding sleeve, the holdingsleeve defining a threaded opening at a proximal end thereof thatreceives a stem that drives the securing foot between a first positionand a second position, the implant holder including a threaded partextending at a predetermined angle from the proximal end of the holdingsleeve that is adapted to engage a complementary threaded region of areduction knob; and a handle assembly comprising two pivotally attachedarms, a rod hook connected to one of the arms and a guide attached tothe other of the arms; and wherein the guide is adapted to slidablyengage the threaded part such that the rod hook is moveable in a firstdirection by threaded interaction of the reduction knob with thethreaded part, and wherein pivotal motion of the arms causes the rodhook to be moveable in a second direction different than the firstdirection.
 6. The medical device of claim 5, wherein a proximal end ofthe stem includes a securing cap.
 7. The medical device of claim 6,wherein a portion of the stem proximate to the securing cap defines athreaded region.
 8. The medical device of claim 5, wherein rotation ofthe stem into the threaded opening of the holding sleeve engages thesecuring foot to the screw head.
 9. The medical device of claim 8,wherein a portion of the securing foot engaging the screw has a knowngeometry and is complementary to a known geometry of the screw.
 10. Themedical device of claim 5, wherein the distal end of the holding sleeveis defined having three sides, and wherein one side of the three sideshas an opening defined therein.
 11. The medical device of claim 5,wherein the predetermined angle of the threaded part of the implantholder is approximately 12°.
 12. The medical device of claim 5, whereinthe first direction is defined as substantially parallel along an axisdefining the threaded part.
 13. The medical device of claim 5, whereinthe second direction is defined as being substantially parallel to anaxis approximated by an arc created by the movement of the rod hook. 14.A medical device for reducing a rod into a head of a screw, comprising:an implant holder that includes a holding sleeve having a proximal endand a distal end, a securing foot pivotally attached to the distal endof the holding sleeve, the holding sleeve defining a threaded openingthat receives a stem that drives the securing foot, the implant holderincluding a threaded part extending from the proximal end of the holdingsleeve that is adapted to engage a complementary threaded region of areduction knob; and a handle assembly comprising two pivotally attachedarms, a rod hook connected to one of the arms and a guide attached tothe other of the arms; and wherein the guide is adapted to slidablyengage the threaded part such that the rod hook is moveable by threadedinteraction of the reduction knob with the threaded part in a firstdirection defined as substantially parallel along an axis defining thethreaded part, and wherein pivotal motion of the arms causes the rodhook to be moveable in a second direction defined as substantiallyparallel along an axis defining an arc that intersects the axis definingthe threaded part.
 15. The medical device of claim 14, wherein rotationof the stem into the threaded opening of the holding sleeve engages thesecuring foot to the screw head.
 16. The medical device of claim 14,wherein a portion of the securing foot that engages the screw has aknown geometry and is complementary to a known geometry of the screw.17. The medical device of claim 14, wherein the guide is attached to therod hook with a pivot screw.